A Novel Methylene Blue Indicator-Based Aptasensor for Rapid Detection of .

is a significant opportunistic pathogen highly prevalent in the environment, requiring early detection methods to prevent infections in vulnerable individuals. The most specific aptamer for , F23, has been used for the development of various assays and sensors for early diagnosis and monitoring. In this study, a novel F23-based electrochemical aptasensor was designed using disposal gold screen-printed electrodes (Au-SPEs) with high reproducibility.

An Electrochemical Aptasensor for the Detection of Freshwater Cyanobacteria.

is a genus of cyanobacteria that is filamentous and nitrogen-fixing and inhabits aquatic environments. This genus is known as one of the major producers of cyanotoxins that can affect water quality after the bloom period. In this study, an electrochemical aptasensor is demonstrated using a specific aptamer to detect sp.

Growth of freshwater cyanobacterium sp. ULC602 in different growing and nutrient conditions.

sp. ULC602, recently isolated in a Belgian lake, is a filamentous, nitrogen-fixing, freshwater cyanobacterium that is one of the primary producers of cyanotoxins following its bloom formation, causing water contamination. This study aims to evaluate the effects of growing conditions and essential nutrients on the growth of sp.

Microbial cell surface display of oxidoreductases: Concepts and applications.

Heterologous proteins anchoring on the living cell surface have recently received significant attention due to their promising application potential in various areas of biotechnology. This work presents an overview of displaying strategies for oxidoreductases, enzymes important in applied biocatalysis. Anchoring systems for oxidoreductase display on Gram-positive and Gram-negative bacteria and yeasts were analysed.

Cell Wall Anchoring of a Bacterial Chitosanase in Using a Food-Grade Expression System and Two Versions of an LP TG Anchor.

Lactic acid bacteria (LAB) have attracted increasing interest recently as cell factories for the production of proteins as well as a carrier of proteins that are of interest for food and therapeutic applications. In this present study, we exploit a lactobacillal food-grade expression system derived from the pSIP expression vectors using the (alanine racemase) gene as the selection marker for the expression and cell-surface display of a chitosanase in using two truncated forms of a LP × TG anchor. CsnA, a chitosanase from 168 (ATCC23857), was fused to two different truncated forms (short-S and long-L anchors) of an LP × TG anchor derived from Lp_1229, a key-protein for mannose-specific adhesion in WCFS1.

Immobilization of β-Galactosidases on the Cell Surface Using the Peptidoglycan-Binding Motif LysM.

Lysin motif (LysM) domains are found in many bacterial peptidoglycan hydrolases. They can bind non-covalently to peptidoglycan and have been employed to display heterologous proteins on the bacterial cell surface. In this study, we aimed to use a single LysM domain derived from a putative extracellular transglycosylase Lp_3014 of WCFS1 to display two different lactobacillal β-galactosidases, the heterodimeric LacLM-type from and the homodimeric LacZ-type from subsp.

β-Galactosidase from DSM 20075: Biochemical Characterization and Recombinant Expression for Applications in Dairy Industry.

β-Galactosidase encoding genes from DSM 20075 were cloned and successfully overexpressed in and using different expression systems. The highest recombinant β-galactosidase activity of ∼26 kU per L of medium was obtained when using an expression system based on the T7 RNA polymerase promoter in , which is more than 1000-fold or 28-fold higher than the production of native β-galactosidase from DSM 20075 when grown on glucose or lactose, respectively. The overexpression in using lactobacillal food-grade gene expression system resulted in ∼2.

Immobilization of β-Galactosidases from Lactobacillus on Chitin Using a Chitin-Binding Domain.

Two β-galactosidases from Lactobacillus, including a heterodimeric LacLM type enzyme from Lactobacillus reuteri L103 and a homodimeric LacZ type β-galactosidase from Lactobacillus bulgaricus DSM 20081, were studied for immobilization on chitin using a carbohydrate-binding domain (chitin-binding domain, ChBD) from a chitinolytic enzyme. Three recombinant enzymes, namely, LacLM-ChBD, ChBD-LacLM, and LacZ-ChBD, were constructed and successfully expressed in Lactobacillus plantarum WCFS1. Depending on the structure of the enzymes, either homodimeric or heterodimeric, as well as the positioning of the chitin-binding domain in relation to the catalytic domains, that is, upstream or downstream of the main protein, the expression in the host strain and the immobilization on chitin beads were different.

Display of a β-mannanase and a chitosanase on the cell surface of Lactobacillus plantarum towards the development of whole-cell biocatalysts.

Background: Lactobacillus plantarum is considered as a potential cell factory because of its GRAS (generally recognized as safe) status and long history of use in food applications. Its possible applications include in situ delivery of proteins to a host, based on its ability to persist at mucosal surfaces of the human intestine, and the production of food-related enzymes. By displaying different enzymes on the surface of L.